The aim of this research is to obtain basic information on mitochondrial chain enzyme systems enabling conclusions on sequence, action and mechanisms of electron and coupled energy transfer by the methods of sequential fragmentation, systematic reconstitution and related physiochemical techniques. This type of attack may open up new avenues leading to more advanced designs for experiments in the field of terminal electron transport systems. Indeed, some of the results obtained from the project in the last few years would not have been discovered by conventional methods, but were dramatically and un-ambiguously revealed by reconstitution experiments. This is a long term project which, of necessity, entails the preliminary isolation and characterization of respiratory components from intra-cellular organelles. BIBLIOGRAPHIC REFERENCES: Ohnishi, T., Salerno, J. C., Winter, D. B., Lim, J., Yu, C. A., Yu, L., and King, T. E. Thermodynamic and EPR Characteristics of Two Ferredoxin-Type Iron-Sulfur Centers in the Succinate-Ubiquinone Reductase Segment of the Respiratory Chain. J. Biol. Chem. 251, 2094-2104 (1976). Ohnishi, T., Lim, J., Winter, D. B., and King, T. E. Thermodynamic and EPR Characteristics of a HiPIP-Type Iron-Sulfur Center in the Succinate Dehydrogenase of the Respiratory Chain. J. Biol. Chem. 251, 2105-2109 (1976).